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SUB-PIXEL REGISTRATION IN COMPUTATIONAL IMAGING AND APPLICATIONS TO ENHANCEMENT OF MAXILLOFACIAL CT DATA
Title
SUB-PIXEL REGISTRATION IN COMPUTATIONAL IMAGING AND APPLICATIONS TO ENHANCEMENT OF MAXILLOFACIAL CT DATA.
Creator
Balci, Murat, Foroosh, Hassan, University of Central Florida
Abstract / Description
In computational imaging, data acquired by sampling the same scene or object at different times or from different orientations result in images in different coordinate systems. Registration is a crucial step in order to be able to compare, integrate and fuse the data obtained from different measurements. Tomography is the method of imaging a single plane or slice of an object. A Computed Tomography (CT) scan, also known as a CAT scan (Computed Axial Tomography scan), is a Helical Tomography,...
Show moreIn computational imaging, data acquired by sampling the same scene or object at different times or from different orientations result in images in different coordinate systems. Registration is a crucial step in order to be able to compare, integrate and fuse the data obtained from different measurements. Tomography is the method of imaging a single plane or slice of an object. A Computed Tomography (CT) scan, also known as a CAT scan (Computed Axial Tomography scan), is a Helical Tomography, which traditionally produces a 2D image of the structures in a thin section of the body. It uses X-ray, which is ionizing radiation. Although the actual dose is typically low, repeated scans should be limited. In dentistry, implant dentistry in specific, there is a need for 3D visualization of internal anatomy. The internal visualization is mainly based on CT scanning technologies. The most important technological advancement which dramatically enhanced the clinician's ability to diagnose, treat, and plan dental implants has been the CT scan. Advanced 3D modeling and visualization techniques permit highly refined and accurate assessment of the CT scan data. However, in addition to imperfections of the instrument and the imaging process, it is not uncommon to encounter other unwanted artifacts in the form of bright regions, flares and erroneous pixels due to dental bridges, metal braces, etc. Currently, removing and cleaning up the data from acquisition backscattering imperfections and unwanted artifacts is performed manually, which is as good as the experience level of the technician. On the other hand the process is error prone, since the editing process needs to be performed image by image. We address some of these issues by proposing novel registration methods and using stonecast models of patient's dental imprint as reference ground truth data. Stone-cast models were originally used by dentists to make complete or partial dentures. The CT scan of such stone-cast models can be used to automatically guide the cleaning of patients' CT scans from defects or unwanted artifacts, and also as an automatic segmentation system for the outliers of the CT scan data without use of stone-cast models. Segmented data is subsequently used to clean the data from artifacts using a new proposed 3D inpainting approach.
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Date Issued
2006
Identifier
CFE0001443, ucf:47040
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001443
A MODEL OF HIP DYSPLASIA REDUCTIONS IN INFANTS USING THE PAVLIK HARNESS
Title
A MODEL OF HIP DYSPLASIA REDUCTIONS IN INFANTS USING THE PAVLIK HARNESS.
Creator
Hadri, Wissam, Samsam, Mohtashem, University of Central Florida
Abstract / Description
Hip dysplasia, also known as congenital dysplasia of the hip (CDH) or Developmental Dysplasia of the Hip (DDH), is a mal-alignment of the hip joint. Left untreated within the first nine months, DDH could lead to permanent disability. Luckily however, this condition is diagnosed at an early age and is usually treated without surgery through the use of the Pavlik harness. In this thesis, a 3D computational model and dynamic finite element analysis of the muscles and tissues involved in hip...
Show moreHip dysplasia, also known as congenital dysplasia of the hip (CDH) or Developmental Dysplasia of the Hip (DDH), is a mal-alignment of the hip joint. Left untreated within the first nine months, DDH could lead to permanent disability. Luckily however, this condition is diagnosed at an early age and is usually treated without surgery through the use of the Pavlik harness. In this thesis, a 3D computational model and dynamic finite element analysis of the muscles and tissues involved in hip dysplasia and the mechanics of the Pavlik harness, as rendered by Dr. Alain J. Kassab's research group in the College of Mechanical and Aerospace Engineering in the University of Central Florida over the past 3 years, were reviewed and discussed to evaluate the accuracy of the hip reduction mechanism. I examine the group's usage of CT-based images to create accurate models of the bony structures, muscle tensions and roles that were generated using biomechanical analyses of maximal and passive strain, and the usage of adult and infant hips. Results, as produced by the group indicated that the effects and force contribution of the muscles studied are functions of severity of hip dislocation. Therefore, I discussed complications with real world-to-computational modeling with regards to structural systems and data interpretations. Although this design could be applied to more anatomical models and mechanistic analyses, more research would have to be completed to create more accurate models and results.
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Date Issued
2014
Identifier
CFH0004641, ucf:45317
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFH0004641
The Dynamic Functions of Bax are Dependent on Key Structural and Regulatory Features
Title
The Dynamic Functions of Bax are Dependent on Key Structural and Regulatory Features.
Creator
Boohaker, Rebecca, Khaled, Annette, Cole, Alexander, Zervos, Antonis, Tatulian, Suren, University of Central Florida
Abstract / Description
Bax is an essential mediator of cell fate. Since its discovery in 1985 as a protein that interacts with the anti-apoptotic protein, Bcl-2, key elements related to its function, structure and regulation remains to be determined. To this end, mitochondrial metabolism was examined in non-apoptotic Bax-deficient HCT-116 cells as well as primary hepatocytes from Bax-deficient mice. Although mitochondrial density and mitochondrial DNA content was the same in Bax-containing and Bax -deficient cells,...
Show moreBax is an essential mediator of cell fate. Since its discovery in 1985 as a protein that interacts with the anti-apoptotic protein, Bcl-2, key elements related to its function, structure and regulation remains to be determined. To this end, mitochondrial metabolism was examined in non-apoptotic Bax-deficient HCT-116 cells as well as primary hepatocytes from Bax-deficient mice. Although mitochondrial density and mitochondrial DNA content was the same in Bax-containing and Bax -deficient cells, MitoTracker staining patterns differed, suggesting the existence of Bax -dependent functional differences in mitochondrial physiology. Oxygen consumption and cellular ATP levels were reduced in Bax -deficient cells, while glycolysis was increased. These results suggest that cells lacking Bax have a deficiency in the ability to generate ATP through cellular respiration, supported by detection of reduced citrate synthase activity in Bax -deficient cells. Expression of either full length or C-terminal truncated Bax in Bax -deficient cells rescued ATP synthesis and oxygen consumption and reduced glycolytic activity, suggesting that this metabolic function of Bax was not dependent upon its C-terminal helix. Expression of BCL-2 in Bax-containing cells resulted in a subsequent loss of ATP measured, implying that, even under non-apoptotic conditions, an antagonistic interaction exists between the two proteins. Bax is composed of nine alpha-helices. While three of these helices have features of a trans-membrane region, the contribution of each domain to the apoptotic or non-apoptotic functions of Bax remains unknown. To examine this, we focused on the C-terminal alpha-9 helix, an amphipathic domain with putative membrane binding properties and discovered that it has an inherent membrane-binding and cytotoxic capacity. A peptide based on the last twenty amino acids (CT20p) of the alpha-9 helix was synthesized and proved a potent inducer of cell death independent of any apoptotic stimuli. The solubility of CT20p allowed it to be encapsulated in polymeric nanoparticles (NPs), and these CT20p-NPs caused the death of colon and breast cancer cells in vitro and induced tumor regression in vivo, using a murine breast cancer tumor model. CT20p caused increased mitochondrial membrane potential followed by cell death via membrane rupture, without the characteristic membrane asymmetry associated with apoptosis. Hence, while CT20p is based on Bax, its innate cytotoxic activity is unlike the parent protein and could be a powerful anti-cancer agent that bypasses drug resistance, can be encapsulated in tumor-targeted nanoparticles and has potential application in combination therapies to activate multiple death pathways in cancer cells. While previous work revealed novel aspects of the biology of Bax that were unrecognized, new structural information is needed to fully elucidate the complexity of Bax's function. One approach is to use computational modeling to assess the solved structure of Bax and provide insight into the structural components involved in the activity of the protein. Use of molecular dynamics simulators such as GROMACS, as well as other computational tools provides a powerful means by which to test the feasibility of certain modifications in defined parameters. Such work revealed that the removal of the C-terminal alpha-9 helix of Bax, which normally resides within a hydrophobic pocket, significantly destabilized the protein, perhaps explaining how the protein transitions from soluble to membrane-bound form and maintain energy production via aerobic respiration or, conversely, how the C-terminus helix conveys cytotoxicity. Collectively, this work reveals that Bax is more than an inducer of cell death but has complex activities yet to be determined.
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Date Issued
2012
Identifier
CFE0004521, ucf:49285
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0004521
Synergistic Visualization And Quantitative Analysis Of Volumetric Medical Images
Title
Synergistic Visualization And Quantitative Analysis Of Volumetric Medical Images.
Creator
Torosdagli, Neslisah, Bagci, Ulas, Hughes, Charles, Jha, Sumit Kumar, Lisle, Curtis, University of Central Florida
Abstract / Description
The medical diagnosis process starts with an interview with the patient, and continues with the physical exam. In practice, the medical professional may require additional screenings to precisely diagnose. Medical imaging is one of the most frequently used non-invasive screening methods to acquire insight of human body. Medical imaging is not only essential for accurate diagnosis, but also it can enable early prevention. Medical data visualization refers to projecting the medical data into a...
Show moreThe medical diagnosis process starts with an interview with the patient, and continues with the physical exam. In practice, the medical professional may require additional screenings to precisely diagnose. Medical imaging is one of the most frequently used non-invasive screening methods to acquire insight of human body. Medical imaging is not only essential for accurate diagnosis, but also it can enable early prevention. Medical data visualization refers to projecting the medical data into a human understandable format at mediums such as 2D or head-mounted displays without causing any interpretation which may lead to clinical intervention. In contrast to the medical visualization, quantification refers to extracting the information in the medical scan to enable the clinicians to make fast and accurate decisions.Despite the extraordinary process both in medical visualization and quantitative radiology, efforts to improve these two complementary fields are often performed independently and synergistic combination is under-studied. Existing image-based software platforms mostly fail to be used in routine clinics due to lack of a unified strategy that guides clinicians both visually and quan- titatively. Hence, there is an urgent need for a bridge connecting the medical visualization and automatic quantification algorithms in the same software platform. In this thesis, we aim to fill this research gap by visualizing medical images interactively from anywhere, and performing a fast, accurate and fully-automatic quantification of the medical imaging data. To end this, we propose several innovative and novel methods. Specifically, we solve the following sub-problems of the ul- timate goal: (1) direct web-based out-of-core volume rendering, (2) robust, accurate, and efficient learning based algorithms to segment highly pathological medical data, (3) automatic landmark- ing for aiding diagnosis and surgical planning and (4) novel artificial intelligence algorithms to determine the sufficient and necessary data to derive large-scale problems.
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Date Issued
2019
Identifier
CFE0007541, ucf:52593
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007541
THE EFFECT OF TECHNOLOGY ACCEPTANCE ON UNDERGRADUATE STUDENTS' USAGE OF WEBCT AS A COLLABORATIVE TOOL
Title
THE EFFECT OF TECHNOLOGY ACCEPTANCE ON UNDERGRADUATE STUDENTS' USAGE OF WEBCT AS A COLLABORATIVE TOOL.
Creator
Yang, Huei-Hsuan, Sivo, Stephen A., University of Central Florida
Abstract / Description
The purpose of this research study was to use the Technology Acceptance Model (Pan, 2003) for re-examination of the relationships between students' attitude toward the use of WebCT and the relevance of the actual usage in light of social presence and sociability. By using Technology Acceptance Model (TAM) developed by F. Davis (1989), this study focused on variables such as perceived usefulness, perceived ease of use, computer self-efficacy, subjective norms, attitude and actual use of...
Show moreThe purpose of this research study was to use the Technology Acceptance Model (Pan, 2003) for re-examination of the relationships between students' attitude toward the use of WebCT and the relevance of the actual usage in light of social presence and sociability. By using Technology Acceptance Model (TAM) developed by F. Davis (1989), this study focused on variables such as perceived usefulness, perceived ease of use, computer self-efficacy, subjective norms, attitude and actual use of WebCT to account for the effect towards the achievement in the exam which is an outcome variable. The data were collected over three different time periods during the spring semester of 2007 to find how these results changed over time. The participants were the students who enrolled in the business marketing course (Principle of marketing) at the University of Central Florida in spring, 2007. The course was divided to three sections: on-campus, video-streaming and online classes. Although there were three different delivery methods, there was only one instructor and they used same material for all sections so the results were used to compare the differences from three classes. The study was conducted by using instruments to measure perceived usefulness, perceived ease of use, computer self-efficacy, subjective norms, actual use, attitude, sociability, social presence and an additional demographic instrument.
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Date Issued
2007
Identifier
CFE0001761, ucf:47262
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001761
EXTENDING THE TECHNOLOGY ACCEPTANCE MODEL USING PERCEIVED USER RESOURCES IN HIGHER EDUCATION WEB-BASED ONLINE LEARNING COURSES
Title
EXTENDING THE TECHNOLOGY ACCEPTANCE MODEL USING PERCEIVED USER RESOURCES IN HIGHER EDUCATION WEB-BASED ONLINE LEARNING COURSES.
Creator
KU, CHENG-HSIN, Sivo, Stephen, University of Central Florida
Abstract / Description
The purpose of this research was to examine students' acceptance of the World Wide Web Course Tools (WebCT) online learning system. The Perceived Resources and Technology Acceptance Model (PRATAM) was created based on previous research to address the factors of perceived resources, perceived usefulness, perceived ease of use, attitude toward using, behavioral intention to use and actual system use. The aim for this research was to investigate the critical determinants and provide the...
Show moreThe purpose of this research was to examine students' acceptance of the World Wide Web Course Tools (WebCT) online learning system. The Perceived Resources and Technology Acceptance Model (PRATAM) was created based on previous research to address the factors of perceived resources, perceived usefulness, perceived ease of use, attitude toward using, behavioral intention to use and actual system use. The aim for this research was to investigate the critical determinants and provide the causal relationships regarding students' acceptance behaviors when using WebCT. While institutions are expecting to adopt online learning to reach more students, there are still many challenges for institutions to retain students in their online courses. The literature review conducted in this research indicated that the Technology Acceptance Model (TAM) has successfully explained students' behaviors when they use educational information systems. In addition, the additional perceived resources variable in the PRATAM also showed a significant influence on the other belief and intention variables. The study analyzed a total of 115 students responses in two surveys administered during two WebCT based courses taught at a large southeastern public university. The beliefs, attitudes, intentions, and behavioral constructs of PRATAM showed significant goodness-of-fit indices and coefficient of determination after analyzing the data in both surveys. However, the results indicated several exceptions on PRATAM's constructs and causal relationships. First, the path coefficient between perceived resources to behavioral intention to use in both pre-test and post-test were insignificant. Second, the path coefficient between behavioral intention to use and actual system use in pre-test was insignificant. Third, the path coefficient between perceived resources and perceived usefulness in post-test were insignificant. In addition, the research also suggested an additional link between perceived ease of use and behavioral intention to use at the pre-test data. Overall, this research validated the influences of PRATAM's constructs factors to students' acceptance behaviors toward WebCT. The findings of this research could provide a guideline for future implementations of online learning systems in higher education.
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Date Issued
2009
Identifier
CFE0002635, ucf:48233
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0002635
Chaperonin Containing TCP1 (CCT) as a Target for Cancer Therapy
Title
Chaperonin Containing TCP1 (CCT) as a Target for Cancer Therapy.
Creator
Carr, Ana, Khaled, Annette, Altomare, Deborah, Tigno-Aranjuez, Justine, Fernandez-Valle, Cristina, University of Central Florida
Abstract / Description
Treatments for aggressive cancers like triple negative breast cancer (TNBC) and small-cell lung cancer (SCLC) have not improved and remain associated with debilitating side effects. There is an unmet medical need for better, druggable targets and improved therapeutics. To this end, we investigated the role of Chaperonin-Containing TCP1 (CCT), an evolutionarily conserved protein-folding complex composed of eight subunits (CCT1-8), in oncogenesis. Our laboratory was the first to report that the...
Show moreTreatments for aggressive cancers like triple negative breast cancer (TNBC) and small-cell lung cancer (SCLC) have not improved and remain associated with debilitating side effects. There is an unmet medical need for better, druggable targets and improved therapeutics. To this end, we investigated the role of Chaperonin-Containing TCP1 (CCT), an evolutionarily conserved protein-folding complex composed of eight subunits (CCT1-8), in oncogenesis. Our laboratory was the first to report that the CCT2 subunit is highly expressed in breast cancer and could be therapeutically targeted. To determine whether CCT is a marker of disease progression in other cancers, we analyzed CCT2 gene expression in liver, prostate and lung cancer, using publicly available genetic databases, and confirmed findings by assessing CCT2 and client proteins, like STAT3, in tumor tissues by immunohistochemistry. We found that CCT2 was high in all cancers, especially SCLC, and correlated with decreased patient survival. We tested CT20p, the peptide therapeutic developed by our laboratory to inhibit CCT, on SCLC and primary lung cells, finding that CT20p was only cytotoxic to SCLC cells. Since SCLC currently lacks targeted therapeutics, our work yielded a new targeted agent that could improve lung cancer mortality. To establish a mechanism of action for CT20p, we partially knocked out CCT2 in TNBC cells, which decreased tumorigenicity in mice and reduced levels of essential proteins like STAT3. To confirm, we overexpressed CCT2 in non-tumorigenic cells and conferred tumor-like characteristics such as increased migration and elevated STAT3. These studies positioned us to develop and validate a strategy for discovery of new small molecule inhibitors of CCT. We thus advanced the field of cancer research by demonstrating that CCT could have diagnostic potential for cancers, such as SCLC and TNBC, that are a significant cause of human death and showed that targeting CCT is a promising therapeutic approach.
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Date Issued
2017
Identifier
CFE0007280, ucf:52191
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007280
Synthesis and Characterization of New Probes for use in Fluorescence and X-ray CT Bioimaging
Title
Synthesis and Characterization of New Probes for use in Fluorescence and X-ray CT Bioimaging.
Creator
Tang, Simon, Belfield, Kevin, Miles, Delbert, Campiglia, Andres, Zou, Shengli, Cheng, Zixi, University of Central Florida
Abstract / Description
The pursuit of more suitable drugs intended for possible biological applications are a continuously growing topic of research within the scientific community. One of these suitable qualities includes the need for hydrophilicity and or some appropriate delivery system for the drug to enter into biological systems. A system of analyzing and following these compounds would then, however, be necessary to conduct any kind of mechanistic or interaction studies for he said drug within the biological...
Show moreThe pursuit of more suitable drugs intended for possible biological applications are a continuously growing topic of research within the scientific community. One of these suitable qualities includes the need for hydrophilicity and or some appropriate delivery system for the drug to enter into biological systems. A system of analyzing and following these compounds would then, however, be necessary to conduct any kind of mechanistic or interaction studies for he said drug within the biological system. Just to name a few, fluorescence and X-ray computed tomography (CT) methods allow for imaging of biological systems but require the need of compounds with specific qualities. Finally, even with a means of entering and following a oaded drug, it would not be complete without a way of targeting its intended location. Herein, the first chapter reports the synthesis and characterization of a fluorene-based pyridil bis-?-diketone compound with suitable one- and two-photon fluorescent properties and its encapsulation into Pluronic F127 micelles for the possible application of tracking lysosomes. Next the synthesis and characterization of a BODIPY-based fluorophore with excellent fluorescence ability is reported. This compound was conjugated to two triphenylphosphine (TPP) groups and is shown as a potential mitochondria probe within HCT-116 cells. Finally, the synthesis and characterization of diatrizoic acid (DA) based derivatives conjugated to silica nanoparticles, as well as unconjugated, are reported as potential CT contrast agents. The derivatives were also functionalized with maleimide moieties facilitating subsequent potential bioconjugation of a targeting protein via a thiol group.
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Date Issued
2015
Identifier
CFE0006056, ucf:50961
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0006056
The Anti-toxin Properties of Grape Seed Phenolic Compounds
Title
The Anti-toxin Properties of Grape Seed Phenolic Compounds.
Creator
Cherubin, Patrick, Teter, Kenneth, Zervos, Antonis, Roy, Herve, Phanstiel, Otto, University of Central Florida
Abstract / Description
Corynebacterium diphtheriae, Pseudomonas aeruginosa, Ricinus communis, Shigella dysentariae, and Vibrio cholerae produce AB toxins which share the same basic structural characteristics: a catalytic A subunit attached to a cell-binding B subunit. All AB toxins have cytosolic targets despite an initial extracellular location. AB toxins use different methods to reach the cytosol and have different effects on the target cell. Broad-spectrum inhibitors against these toxins are therefore hard to...
Show moreCorynebacterium diphtheriae, Pseudomonas aeruginosa, Ricinus communis, Shigella dysentariae, and Vibrio cholerae produce AB toxins which share the same basic structural characteristics: a catalytic A subunit attached to a cell-binding B subunit. All AB toxins have cytosolic targets despite an initial extracellular location. AB toxins use different methods to reach the cytosol and have different effects on the target cell. Broad-spectrum inhibitors against these toxins are therefore hard to develop because they use different surface receptors, entry mechanisms, enzyme activities, and cytosolic targets.We have found that grape seed extract provides resistance to five different AB toxins: diphtheria toxin (DT), P. aeruginosa exotoxin A (ETA), ricin, Shiga toxin, and cholera toxin (CT). To identify individual compounds in grape seed extract that are capable of inhibiting the activities of these AB toxins, we screened twenty common phenolic compounds of grape seed extract for anti-toxin properties. Three compounds inhibited DT, four inhibited ETA, one inhibited ricin, and twelve inhibited CT. Additional studies were performed to determine the mechanism of inhibition against CT. Two compounds inhibited CT binding to the cell surface and even stripped bound CT off the plasma membrane of a target cell. Two other compounds inhibited the enzymatic activity of CT. We have thus identified individual toxin inhibitors from grape seed extract and some of their mechanisms of inhibition against CT. This work will help to formulate a defined mixture of phenolic compounds that could potentially be used as a therapeutic against a broad range of AB toxins.
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Date Issued
2014
Identifier
CFE0005315, ucf:50510
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0005315